Conventionally, a damper device has two diaphragms, and peripheral parts of the two diaphragms are welded with each other. The damper device is arranged in a fuel chamber of a high pressure pump. Pressure pulsation of fuel is reduced by changing the volume of a damper chamber according to the pressure of fuel in the fuel chamber.
JP-2010-7693A describes a damper device having a resin component which covers the peripheral parts of the two diaphragms. When the damper device is mounted to a high pressure pump, the damper device is fixed between a base of the housing and a retainer at plural positions in the circumference direction.
In JP-2010-7693A, the resin component which covers the peripheral parts of the diaphragms is made of resin, and not all the circumference of the peripheral parts of the diaphragms are covered with the base and the retainer. Each of the diaphragms is deformed when the volume of the damper chamber becomes large according to the pressure of fuel. At this time, the peripheral parts of the diaphragms may be deformed to be separated from each other. In this case, the stress caused by the deformation may act on the weld part.
Moreover, when the damper device is manufactured, it is necessary to mold the resin component around the peripheral parts after welding, so the number of manufacture processes is increased.